A molecular mechanism for osmolyte-induced protein stability.

ABSTRACT: Osmolytes are small organic compounds that affect protein stability and are ubiquitous in living systems. In the equilibrium protein folding reaction, unfolded (U) native (N), protecting osmolytes push the equilibrium toward N, whereas denaturing osmolytes push the equilibrium toward U. As yet, there is no universal molecular theory that can explain the mechanism by which osmolytes interact with the protein to affect protein stability. Here, we lay the groundwork for such a theory, starting with a key observation: the transfer free energy of protein backbone from water to a water/osmolyte solution, Deltagtr, is negatively correlated with an osmolyte's fractional polar surface area. Deltagtr measures the degree to which an osmolyte stabilizes a protein. Consequently, a straightforward inter

SUBMITTER: Street TO 

PROVIDER: S-EPMC1564065 | biostudies-literature | 2006 Sep

REPOSITORIES: biostudies-literature